engine RAM CHASSIS CAB 2022 Service Manual

106STARTING AND OPERATING
If the vehicle is not in PARK and the driver turns off
the engine, the vehicle may AutoPark.
AutoPark will engage when all of these conditions
are met:
Vehicle is equipped with a rotary shifter and an
8-speed transmission
Vehicle is not in PARK
Vehicle speed is 1.2 mph (1.9 km/h) or less
Ignition is switched from ON/RUN to ACC
NOTE:For Keyless Enter ‘n Go™ equipped vehicles, the
engine will turn off and the ignition switch will
change to ACC position. After 30 minutes the
ignition switches to OFF automatically, unless the
driver turns the ignition switch OFF. If the vehicle is not in PARK and the driver exits the
vehicle with the engine running, the vehicle may
AutoPark.
AutoPark will engage when all of these conditions
are met:
Vehicle is equipped with a rotary shifter and an
8-speed transmission
Vehicle is not in PARK
Vehicle speed is 1.2 mph (1.9 km/h) or less
Driver’s seat belt is unbuckled
Driver’s door is ajar
Brake pedal is not pressed
The message “ AutoPark Engaged Shift to P then
Shift to Gear ” will display in the instrument cluster.
NOTE:In some cases the ParkSense graphic will be
displayed in the instrument cluster, causing the
“AutoPark Engaged Shift to P then Shift to Gear ” to
not be seen. In these cases, the shifter must be
returned to “P” to select desired gear.
If the driver shifts into PARK while moving, the
vehicle may AutoPark.
AutoPark will engage ONLY when vehicle speed is
1.2 mph (1.9 km/h) or less.
The message “ Vehicle Speed is Too High to Shift to
P” will be displayed in the instrument cluster if
vehicle speed is above 1.2 mph (1.9 km/h). 4WD Low — If Equipped
AutoPark will be disabled when operating the
vehicle in 4WD LOW.
The message “
AutoPark Disabled ” will be
displayed in the instrument cluster.
Additional customer warnings will be given when
all of these conditions are met:Vehicle is not in PARK
Driver’s door is ajar
Vehicle is in 4WD Low range
The message “ AutoPark Not Engaged” will be
displayed in the instrument cluster. A warning
chime will continue until you shift the vehicle into
PARK or the driver’s door is closed.
ALWAYS DO A VISUAL CHECK
that your vehicle is in
PARK by looking for the “P” in the instrument
cluster display and near the shifter. As an added
precaution, always apply the parking brake when
exiting the vehicle.
AutoPark is a supplemental feature. It is not
designed to replace the need to shift your
vehicle into PARK. It is a back up system and
should not be relied upon as the primary
method by which the driver shifts the vehicle
into PARK.
WARNING!WARNING!

If vehicle speed is above 1.2 mph (1.9 km/h), the
transmission will default to NEUTRAL until the
vehicle speed drops below 1.2 mph (1.9 km/h). A
vehicle left in the NEUTRAL position can roll. As
an added precaution, always apply the parking
brake when exiting the vehicle.

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STARTING AND OPERATING107
TIP START FEATURE
Do not press the accelerator. Place the ignition
switch briefly to the START position and release it.
The starter motor will continue to run and will
automatically disengage when the engine is
running.
KEYLESS ENTER ‘N GO™ — IGNITION
This feature allows the driver to operate the
ignition switch with the push of a button, as long as
the Remote Start/Keyless Enter ‘n Go™ key fob is
in the passenger compartment.
NORMAL STARTING USING ENGINE
START/S TOP B
UTTON
To Turn On The Engine Using The ENGINE START/
STOP Button

1. The transmission must be in PARK.

2. Press and hold the brake pedal while pushing
the ENGINE START/STOP button once.
3. The system takes over and attempts to start the vehicle. If the vehicle fails to start, the
starter will disengage automatically after
10 seconds.
4. If you wish to stop the cranking of the engine prior to the engine starting, push the ENGINE
START/STOP button again.
NOTE:Normal starting of either a cold or a warm engine is
obtained without pumping or pressing the accel -
erator pedal.
To Turn Off The Engine Using ENGINE START/STOP
Button

1. Place the gear selector in PARK, then push and release the ENGINE START/STOP button.

2. The ignition will return to the OFF position.
3. If the gear selector is not in PARK, the ENGINE START/STOP button must be held for two
seconds or three short pushes in a row with
the vehicle speed above 5 mph (8 km/h) before the engine will shut off. The ignition will
remain in the ACC position until the gear
selector is in PARK and the button is pushed
twice to the OFF position.
4. If the gear selector is not in PARK and the ENGINE START/STOP button is pushed once
with the vehicle speed above 5 mph (8 km/h), the instrument cluster will display a “ Vehicle
Not In Park ” message and the engine will
remain running. Never leave a vehicle out of
the PARK position, or it could roll.
NOTE:If the gear selector is not in PARK, and the ENGINE
START/STOP button is pushed once with the
vehicle speed below 5 mph (8 km/h), the engine
will shut off and the ignition will remain in the ACC position. If vehicle speed drops below 1.2 mph
(1.9 km/h), the vehicle may AutoPark
Ú
page 105.
ENGINE START/STOP Button Functions — With
Driver’s Foot OFF The Brake Pedal (In PARK Or
NEUTRAL Position)
The ENGINE START/STOP button operates similar
to an ignition switch. It has three positions: OFF,
ACC, and RUN. To change the ignition positions
without starting the vehicle and use the
accessories, follow these directions:

1. Start with the ignition in the OFF position.

2. Push the ENGINE START/STOP button once to place the ignition to the ACC position.
3. Push the ENGINE START/STOP button a second time to place the ignition to the ON/
RUN position.
4. Push the ENGINE START/STOP button a third time to return the ignition to the OFF position.
If Engine Fails To Start
If the engine fails to start after you have followed
the “Normal Starting” procedure, it may be
flooded. Push the accelerator pedal all the way to
the floor and hold it there while the engine is
cranking. This should clear any excess fuel in case
the engine is flooded.
The starter motor will engage automatically, run for
10 seconds, and then disengage. Once this occurs,
4

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108STARTING AND OPERATING
release the accelerator pedal and the brake pedal,
wait 10 to 15 seconds, then repeat the “Normal
Starting” procedure. If the engine has been flooded, it may start to run,
but not have enough power to continue running
when the ignition button/key is released. If this
occurs, continue cranking with the accelerator
pedal pushed all the way to the floor. Release the
accelerator pedal and the ignition button/key once
the engine is running smoothly.
If the engine shows no sign of starting after a
10 second period of engine cranking with the
accelerator pedal held to the floor, wait 10 to
15 seconds, then repeat the “Normal Starting”
procedure.
COLD WEATHER OPERATION
(BELOW –22°F OR −30°C)
To ensure reliable starting at these temperatures,
use of an externally powered electric engine block
heater (available from an authorized dealer) is
recommended.
AFTER STARTING
The idle speed is controlled automatically, and it
will decrease as the engine warms up.
STARTING THE ENGINE — DIESEL ENGINE
Before starting your vehicle, adjust your seat,
adjust both inside and outside mirrors, and fasten
your seat belts.The starter should not be operated for more than
25-second intervals. Waiting a few minutes
between such intervals will protect the starter from
overheating.
WARNING!
Never pour fuel or other flammable liquid into
the throttle body air inlet opening in an
attempt to start the vehicle. This could result
in flash fire causing serious personal injury.
Do not attempt to push or tow your vehicle to
get it started. Vehicles equipped with an auto
-
matic transmission cannot be started this
way. Unburned fuel could enter the catalytic
converter and once the engine has started,
ignite and damage the converter and vehicle.
If the vehicle has a discharged battery,
booster cables may be used to obtain a start
from a booster battery or the battery in
another vehicle. This type of start can be
dangerous if done improperly Ú page 320.
CAUTION!
To prevent damage to the starter, do not crank
the engine for more than 10 seconds at a time.
Wait 10 to 15 seconds before trying again.
WARNING!
Do not leave children or animals inside parked
vehicles in hot weather. Interior heat build-up
may cause serious injury or death.
When leaving the vehicle, always remove the
key fob and lock your vehicle.
Never leave children alone in a vehicle, or with
access to an unlocked vehicle. Allowing chil -
dren to be in a vehicle unattended is
dangerous for a number of reasons. A child or
others could be seriously or fatally injured.
Children should be warned not to touch the
parking brake, brake pedal or the gear
selector. Do not leave the key fob in or near
the vehicle (or in a location accessible to chil -
dren), and do not leave the ignition of a
vehicle equipped with Keyless Enter ‘n Go™ in
the ACC or ON/RUN position. A child could
operate power windows, other controls, or
move the vehicle.

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STARTING AND OPERATING109
AUTOMATIC TRANSMISSION
Start the engine with the transmission in the
NEUTRAL or PARK position. Apply the brake before
shifting to any driving range.
Tip Start Feature
Do not press the accelerator. Place the ignition
switch briefly to the START position and release it.
The starter motor will continue to run and will
automatically disengage when the engine is
running.
KEYLESS ENTER ‘N GO™ — IGNITION
This feature allows the driver to operate the
ignition switch with the push of a button, as long as
the Remote Start/Keyless Enter ‘n Go™ key fob is
in the passenger compartment.
Normal Starting
USING THE ENGINE START/STOP BUTTON

1. The transmission must be in PARK or NEUTRAL.

2. Press and hold the brake pedal while pushing the ENGINE START/STOP button once.
3. The system takes over and attempts to start the vehicle. If the vehicle fails to start, the
starter will disengage automatically after 25
seconds. 4. If you wish to stop the cranking of the engine
prior to the engine starting, remove your foot
from the brake pedal and push the ENGINE
START/STOP button again.
NOTE:
Normal starting of either a cold or a warm
engine is obtained without pumping or pressing
the accelerator pedal.
Under cold weather conditions, the engine may
not immediately crank if the "Wait to Start" tell -
tale is illuminated. This is normal operation. For
vehicles equipped with Keyless Enter ‘n Go™,
the vehicle will automatically crank when the
"Wait to Start" time has elapsed Ú page 111.
TO TURN OFF THE ENGINE USING ENGINE
START/STOP BUTTON

1. Place the gear selector in PARK, then push
and release the ENGINE START/STOP button.

2. The ignition will return to the OFF position.
3. If the gear selector is not in PARK and the ENGINE START/STOP button is pushed once,
the instrument cluster will display a “Vehicle
Not In Park” message and the engine will
remain running. Never leave a vehicle out of
the PARK position, or it could roll.
4. If the gear selector is in NEUTRAL, and the vehicle speed below 5 mph (8 km/h), pushing the ENGINE START/STOP button once will turn
the engine off. The ignition will remain in the
ACC position.
5. If the vehicle speed is above 5 mph (8 km/h), the ENGINE START/STOP button must be held
for two seconds (or three short pushes in a
row) to turn the engine off. The ignition will
remain in the ACC position (NOT the OFF
position) if the engine is turned off when the
transmission is not in PARK.
NOTE:If the ignition is left in the ACC or ON/RUN (engine
not running) position and the transmission is in
PARK, the system will automatically time out after
30 minutes of inactivity and the ignition return to
the OFF position.
ENGINE START/STOP BUTTON FUNCTIONS —
WITH DRIVER’S FOOT OFF THE BRAKE PEDAL
(IN PARK OR NEUTRAL POSITION)
The ENGINE START/STOP button operates similar
to an ignition switch. It has three positions: OFF,
ACC, and RUN. To change the ignition switch
positions without starting the vehicle and use the
accessories follow these steps:

1. Start with the ignition in the OFF position.

2. Push the ENGINE START/STOP button once to change the ignition to the ACC position.
4

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110STARTING AND OPERATING
3. Push the ENGINE START/STOP button a second time to change the ignition to the RUN
position.
4. Push the ENGINE START/STOP button a third time to return the ignition to the OFF position.
Keyless Enter ‘n Go™ Starting Procedure —
Engine Manifold Air Temperature 0°F To
66°F (–18°C to 19°C)
NOTE:The temperature displayed in the instrument
cluster does not necessarily reflect the engine
manifold air temperature Ú page 81. When
engine temperatures fall below 66°F (19°C) the
“Wait To Start” telltale will remain on indicating the
intake air heater system is active.
Follow the steps in the “Normal Starting”
procedure except:

1. Pushing the engine start button with the driver’s foot on the brake will move the
ignition from OFF or ACC to RUN, and will
illuminate the "Wait to Start" telltale. The
engine will not immediately crank, this is
normal operation.

2. The “Wait to Start" telltale will remain on for a period of time that varies depending on the
engine temperature. 3. While the "Wait to Start" telltale is on, the
instrument cluster will additionally display a
gauge or bar whose initial length represents
the full "Wait to Start" time period. Its length
will decrease until it disappears when the
"Wait to Start" time has elapsed.
4. After the engine “Wait to Start” telltale goes off, the engine will automatically crank.
5. After engine start-up, check to see that there is oil pressure.
6. Release the parking brake and drive.
NOTE:
Engine idle speed will automatically increase to
1,000 RPM and engage the Variable Geometry
Turbocharger at low coolant temperatures to
improve engine warm-up.
The engine will not automatically crank after the
engine "Wait to Start" telltale goes off if a door
or the hood is ajar.
If the engine stalls, or if the ignition switch is left
ON for more than two minutes after the “Wait to
Start” telltale goes out, reset the intake air
heater by turning the ignition switch to the OFF
position for at least 5 seconds and then back
ON. Repeat steps 1 through 6 of “Keyless
Enter ‘n Go™ Starting Procedure – Engine Mani -
fold Air Temperature 0°F To 66°F (–18°C to
19°C).”
EXTREME COLD WEATHER
The Cummins® Turbo Diesel engine is equipped
with several features designed to assist cold
weather starting and operation:
The engine block heater is a resistance heater
installed in the water jacket of the engine just
above and behind the oil filter. It requires a
110–115 Volt AC electrical outlet with a
grounded, three-wire extension cord.
CAUTION!
If the Water in Fuel Indicator Light remains on,
DO NOT START the engine before you drain the
water from the fuel filters to avoid engine
damage Ú page 347.
CAUTION!
Do not crank engine for more than 25 seconds
at a time or starter motor damage may result.
Turn the ignition switch to the OFF position and
wait at least two minutes for the starter to cool
before repeating start procedure.

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STARTING AND OPERATING111
NOTE:The engine block heater cord is a factory installed
option. If your vehicle is not equipped, heater cords
are available from an authorized Mopar® dealer.
A 12 Volt heater built into the fuel filter housings
aid in preventing fuel gelling. It is controlled by a
built-in thermostat.
An intake air heater system both improves
engine starting and reduces the amount of
white smoke generated by a warming engine.
NORMAL STARTING PROCEDURE —
E
NGINE MANIFOLD AIR TEMPERATURE
A
BOVE 66°F (19°C)
Observe the instrument panel cluster lights when
starting the engine.

1. Always apply the parking brake.

2. Shift into PARK for an automatic transmission.
3. Place the ignition switch in the ON/RUN
position and watch the instrument panel
cluster lights. 4. Place the ignition switch in the START position
and crank the engine. Do not press the
accelerator during starting.
5. Check that the Oil Pressure Warning Light has turned off.
6. Release the parking brake.STARTING PROCEDURE — ENGINE
M
ANIFOLD AIR TEMPERATURE 0°F TO
66°F (–18°C
TO 19°C)
NOTE:The temperature displayed in the instrument
cluster does not necessarily reflect the engine
manifold air temperature Ú page 81. When
engine temperatures fall below 66°F (19°C) the
“Wait To Start” telltale will remain on indicating the
intake air heater system is active.
Follow the steps in the “Normal Starting”
procedure except:
1. The “Wait to Start” telltale will remain on for a
period of time that varies depending on the
engine temperature.

2. While the “Wait to Start” telltale is on, the instrument cluster will additionally display a
gauge or bar whose initial length represents
the full “Wait to Start” time period. Its length
will decrease until it disappears when the
“Wait to Start” time has elapsed.
3. After the “Wait to Start” telltale goes off, place the ignition switch in the START position. Do
not press the accelerator during starting.
CAUTION!
If the Water in Fuel Indicator Light remains on,
DO NOT START the engine before you drain the
water from the fuel filters to avoid engine
damage Ú page 347.
CAUTION!
Do not crank engine for more than 25 seconds
at a time or starter motor damage may result.
Turn the ignition switch to the OFF position and
wait at least two minutes for the starter to cool
before repeating start procedure.
CAUTION!
If the Water in Fuel Indicator Light remains on,
DO NOT START the engine before you drain the
water from the fuel filters to avoid engine
damage Úpage 347.
CAUTION!
Do not crank engine for more than 25 seconds
at a time or starter motor damage may result.
Turn the ignition switch to the OFF position and
wait at least two minutes for the starter to cool
before repeating start procedure.
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112STARTING AND OPERATING
4. After engine start-up, check that the Oil Pressure Warning Light has turned off.
5. Release the parking brake and drive.
NOTE:
Engine idle speed will automatically increase to
1,000 RPM and engage the Variable Geometry
Turbocharger at low coolant temperatures to
improve engine warm-up.
Automatic equipped vehicles with optional
Keyless Enter ‘n Go™ – If the ENGINE START/
STOP button is pushed once while in PARK with
the ignition off and driver’s foot on the brake
pedal, the vehicle will automatically crank and
start after the “Wait to Start” time has elapsed.
If it is desired to abort the start process before it
completes, the driver’s foot should be fully
removed from the brake pedal prior to pushing
the start button again in order for the ignition to
move directly to off.
If the engine stalls, or if the ignition switch is left
on for more than two minutes after the “Wait To
Start” telltale goes out, reset the intake air
heater by turning the ignition switch to the OFF
position for at least five seconds and then back
to the ON/RUN position. Repeat steps 1 through
5 of “Starting Procedure – Engine Manifold Air
Temperature 0°F To 66°F (–18°C to 19°C).”
STARTING PROCEDURE — ENGINE
M
ANIFOLD AIR TEMPERATURE BELOW
0°F (-18°C)
In extremely cold weather below 0°F (-18°C) it
may be beneficial to cycle the intake air heater
twice before attempting to start the engine. This
can be accomplished by turning the ignition to OFF
position for at least five seconds and then back to
the ON/RUN position after the “Wait to Start”
telltale has turned off, but before the engine is
started. However, excessive cycling of the intake
air heater will result in damage to the heater
elements or reduced battery voltage.
NOTE:If multiple pre-heat cycles are used before starting,
additional engine run time may be required to
maintain battery state of charge at a satisfactory
level.

1. If the engine stalls after the initial start, the
ignition must be turned to the OFF position for
at least five seconds and then to the ON/RUN
position to recycle the intake air heater.

NOTE:Excessive white smoke and poor engine perfor -
mance will result if intake air heater is not recycled.
2. Heat generated by the intake air heater dissipates rapidly in a cold engine. If more than
two minutes pass between the time the “Wait to Start” telltale turns off and the engine is
started, recycle the intake air heater by turning
the ignition switch to the OFF position for at
least five seconds and then back to the ON/
RUN position.
3. If the vehicle is driven and vehicle speed exceeds 19 mph (31 km/h) before the intake
air heater post-heat (after start) cycle is
complete, the intake air heater will shut off.
4. If the engine is cranked for more than 10 seconds, the post-heat cycle will turn off.
NOTE:
Engine idle speed will automatically increase to
1,000 RPM and engage the Variable Geometry
Turbocharger at low coolant temperatures to
improve engine warm-up.
When a diesel engine is allowed to run out of
fuel or the fuel gels at low temperatures, air is
pulled into the fuel system. If your engine has
run out of fuel Ú page 350.
If the engine stalls, or if the ignition switch is left
on for more than two minutes after the “Wait to
Start” telltale goes out, reset the intake air
heater by turning the ignition switch to the OFF
position for at least five seconds and then back
to the ON/RUN position. Repeat steps 1 through
5 of “Starting Procedure – Engine Manifold Air
Temperature 0°F to 60°F (-18°C to 19°C).”

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STARTING AND OPERATING113
STARTING FLUIDS
The engine is equipped with an automatic electric
air preheating system. If the instructions in this
manual are followed, the engine should start in all
conditions.
NORMAL OPERATION — DIESEL ENGINE
Observe the following when the engine is
operating.
All message center lights are off.
Malfunction Indicator Light (MIL) is off.
Engine oil pressure is above 10 psi (69 kPa) at
idle.
Voltmeter operation:
The voltmeter may show a gauge fluctuation at
various engine temperatures. This cycling
operation is caused by the post-heat cycle of the
intake manifold heater system. The number of
cycles and the length of the cycling operation is
controlled by the engine control module. Post-heat
operation can run for several minutes, and then
the electrical system and voltmeter needle will
stabilize.
The cycling action will cause temporary dimming of
the headlamps, interior lamps, and also a
noticeable reduction in blower motor speed.
WARNING!
Starting fluids or flammable liquids must never
be used in the Cummins® diesel engine (see
Warning label). Never pour diesel fuel,
flammable liquid, starting fluids (ether) into the
air cleaner canister, air intake piping, or
turbocharger inlet in an attempt to start the
vehicle. This could result in a flash fire and
explosion causing serious personal injury and
engine damage.
WARNING!
Do not leave children or animals inside parked
vehicles in hot weather. Interior heat build-up
may cause serious injury or death.
When leaving the vehicle, always remove the
key fob and lock your vehicle.
Never leave children alone in a vehicle, or with
access to an unlocked vehicle. Allowing chil -
dren to be in a vehicle unattended is
dangerous for a number of reasons. A child or
others could be seriously or fatally injured.
Children should be warned not to touch the
parking brake, brake pedal or the gear
selector. Do not leave the key fob in or near
the vehicle (or in a location accessible to chil -
dren), and do not leave the ignition of a
vehicle equipped with Keyless Enter ‘n Go™ in
the ACC or ON/RUN position. A child could
operate power windows, other controls, or
move the vehicle.
4

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114STARTING AND OPERATING
COLD WEATHER PRECAUTIONS
Operation in ambient temperature below 32°F
(0°C) may require special considerations. The
following charts suggest these options:
Fuel Operating Range
NOTE:Use Ultra Low Sulfur Diesel (ULSD) Fuels ONLY.

Fuel Operating Range Chart

*Number 1 ULSD Fuel should only be used where
extended arctic conditions (0°F/-18°C) exist.
NOTE:
Use of Climatized ULSD or Number 1 ULSD Fuel
results in a noticeable decrease in fuel
economy.
Climatized ULSD Fuel is a blend of Number 2
ULSD and Number 1 ULSD Fuels which reduces
the temperature at which wax crystals form in
fuel.
The fuel grade should be clearly marked on the
pump at the fuel station.
The engine requires the use of ULSD Fuel. Use
of incorrect fuel could result in engine and
exhaust system damage Ú page 399.
If climatized or diesel Number 1 ULSD Fuel is
not available, and you are operating below
(20°F/-6°C), in sustained arctic conditions,
Mopar® Premium Diesel Fuel Treatment (or
equivalent) is recommended to avoid gelling
(see Fuel Operating Range Chart).

Under some circumstances increased engine
noise may be audible in the seconds following a
cold start. This is most likely to occur when using
fuel that isn't blended for the ambient tempera -
ture present. This may occur on an unseasonably
cold day or when a truck is fueled in a warmer
climate and driven to a colder climate. The noise
can typically be prevented by using Mopar®
Premium Diesel Fuel Treatment as recom -
mended (see Fuel Operating Range Chart).

Engine Oil Usage
For the correct engine oil viscosity Ú page 341.
Winter Front Cover Usage
A Winter front or cold weather cover is to be used
in ambient temperatures below 32°F (0°C),
especially during extended idle conditions. This
cover is equipped with four flaps for managing
total grille opening in varying ambient
temperatures. If a Winter front or cold weather
cover is to be used the flaps should be left in the
full open position to allow air flow to the charge air
cooler and automatic transmission oil cooler.
When ambient temperatures drop below 0°F
(-17°C) the four flaps need to be closed. A suitable
cold weather cover is available from a Mopar®
dealer.
Battery Blanket Usage
A battery loses 60% of its cranking power as the
battery temperature decreases to 0°F (-18°C). For
the same decrease in temperature, the engine
requires twice as much power to crank at the same
RPM. The use of 120 Volt AC powered battery
blankets will greatly increase starting capability at
low temperatures. Suitable battery blankets are
available from an authorized Mopar® dealer.

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STARTING AND OPERATING115
Engine Warm-Up
Avoid full throttle operation when the engine is
cold. When starting a cold engine, bring the engine
up to operating speed slowly to allow the oil
pressure to stabilize as the engine warms up.
NOTE:High-speed, no-load running of a cold engine can
result in excessive white smoke and poor engine
performance. No-load engine speeds should be
kept under 1,000 RPM during the warm-up period,
especially in cold ambient temperature conditions.
Your vehicle is equipped with an engine warm-up
protection feature that may limit engine
performance after cold starting at low ambient
temperatures. The length of time engine speed is
limited is dependent upon engine coolant
temperature. Engine speed may be briefly limited
to 1,000 RPM after starting with coolant
temperature below freezing conditions, and may
be limited to 1,000 RPM for up to approximately
two minutes under more severe cold conditions.
NOTE:If ambient temperatures are low and the coolant
temperature is below 180°F (82°C), the engine
idle speed will slowly increase to 1,000 RPM after
two minutes of idle, if the following conditions are
met:
Foot is off brake pedal and throttle pedal.
Automatic transmission is in PARK.
Vehicle speed is 0 mph (0 km/h).
Applying the throttle will cancel fast idle.
Operating the exhaust brake at idle will greatly
improve warm-up rate and will help keep the
engine close to operating temperature during
extended idle.
ENGINE IDLING
Avoid prolonged idling. Long periods of idling may
be harmful to your engine because combustion
chamber temperatures can drop so low that the
fuel may not burn completely. Incomplete
combustion allows carbon and varnish to form on
piston rings, engine valves, and injector nozzles.
Also, the unburned fuel can enter the crankcase,
diluting the oil and causing rapid wear to the
engine.
If the engine is allowed to idle or the truck is driven
on low engine speed drive cycles for more than two
hours, the system will automatically enter an
emissions operating mode that will increase the
engine idle speed to 900 RPM (1,050 RPM for
Chassis Cab). While in this mode, which is
designed to help maintain the Diesel Particulate
Filter, the engine idle speed will return to normal
when the brake pedal is applied. A small change in
engine tone or a slight change in engine
performance while accelerating may also be
noticeable at speeds below 20 mph (32 km/h). This operating mode may last for up to an hour of
idle time, or around 20 minutes of driving time.
Your truck may have been ordered with an optional
voltage monitoring idle up feature. If a load is
placed on the electrical system while the truck is in
PARK, this feature will attempt to maintain normal
system voltage by automatically increasing engine
idle speed. You may notice several consecutive
increases in idle speed, up to a maximum of
1,450 RPM, as the system will attempt to utilize
the smallest increase in idle speed necessary to
maintain normal system voltage. The idle speed
will return to normal when either the electrical load
is removed, or when the brake pedal is applied.
NOTE:For instrument cluster display messages related to
the vehicle's exhaust system Ú
page 81.
Idle-Up Feature
The driver-controlled high idle speed feature will
help increase cylinder temperatures and provide
additional cab heat, however, excessive idling may
still cause the exhaust after-treatment system to
not properly regenerate. Extended periods of idle
time should be avoided.
The Idle-Up feature uses the Cruise Control buttons
to increase engine idle speed and quickly warm the
vehicle's interior.
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